Carol Jennings

Carol Joyce Jennings ( Bexon; 25 March 1954 – 29 March 2024) was a British campaigner and advocate for research into Alzheimer's disease. She served as an honorary Vice-President of the Alzheimer's Society until her death in 2024. This mutation, found on the Amyloid Precursor Protein (APP) gene located on chromosome 21, marked a significant breakthrough in understanding the genetic basis of Alzheimer's disease and provided evidence for the development of the 'amyloid hypothesis', which attempts to explain the underlying causes of Alzheimer's disease.

Early life and biography Jennings was born in Nottingham, England, to Joyce and Walter Bexon. She received her education at Bilborough Grammar School and later attended Chester College, where she completed her teacher training. She went on to marry Stuart Jennings, a Methodist minister and historian, and they had two children. It was during this period that her father, Walter, in his mid-50s at the time, began to exhibit symptoms of Alzheimer's disease.

Discovery of the London Mutation By the mid-1980s, three of Walter's siblings also displayed signs of Alzheimer's disease, with symptoms emerging much earlier than expected—in their 40s and 50s. Convinced that there must be a genetic link and determined to find answers, Jennings wrote a letter to the research team led by John Hardy in the spring of 1986. At that time, Hardy was an Assistant Professor of Biochemistry at St. Mary's Hospital, Imperial College London.

The breakthrough came in 1991. Alison Goate, a junior researcher on the team, uncovered the specific gene mutation responsible for the disease in Jennings’s family. Goate, now a professor at Icahn School of Medicine at Mount Sinai, NY, later recalled the discovery as a "eureka moment." with a summary reported in the British press on 16 February.

The mutation, known as the 'London mutation,' affects the amyloid precursor protein (APP) gene, leading to the formation of amyloid plaques in the brain. Amyloid disrupts normal brain processes by overactivating brain cells and causing ongoing inflammation. It can also impact blood flow and have an impact on other proteins in the brain. When excessive amyloid accumulates, it can interact with the toxic protein tau, causing neuronal death and the symptoms of Alzheimer's disease. In those with genetic Alzheimer’s, this process occurs early because the patient produces too much APP. However, the same process also happens in those with non-genetic Alzheimer’s, albeit at a slower rate. During this period, Jennings also worked alongside Penelope Roques and Jill Walton to support members of the Pick's Disease Support Group, the forerunner of what would later become Rare Dementia Support (RDS), a world-leading service for people affected by rare dementias based at the UCL Dementia Research Centre. She is credited as the first support adviser of that group, years before the organisation formally came into existence.

As the amyloid cascade hypothesis gained momentum, Professor Hardy received recognition for his contributions to the field. In 2015, Hardy became the UK's first recipient of the Breakthrough Prize in Life Sciences for "discovering mutations in the amyloid precursor protein (APP) gene that cause early-onset Alzheimer's disease, linking the accumulation of APP-derived beta-amyloid peptide to Alzheimer's pathogenesis, and inspiring new strategies for disease prevention." In his acceptance speech for this award, he expressed special gratitude to Jennings's family. In 2018, Hardy, alongside Christian Haass, Bart De Strooper and Michel Goedert, was honoured with the Brain Prize for "ground-breaking research on the genetic and molecular basis of Alzheimer's disease."

Over time, researchers have expanded upon and challenged this hypothesis, but developing drugs that target amyloid proteins has proven to be a significant challenge, with many failures, underwhelming results, and dangerous side effects reported.

When Jennings herself began to develop symptoms of Alzheimer's disease in 2008, she took a step back from her speaking and advocacy work. However, with the development of new and successful anti-amyloid treatments, journalists and researchers rekindled their interest in the origins of the amyloid hypothesis and Carol Jennings's involvement.

One such success was shown in a large-scale trial of the monoclonal antibody treatment lecanemab. Professor Hardy described the outcome as both "modest" and "historic," and hailed it as the beginning of the end for Alzheimer's disease. In particular, there is hope that anti-amyloid therapies could eventually be used to prevent the disease ever progressing to the symptomatic stage. This resulted in renewed press interest in the Jennings family, and their contribution was once again covered by the press.

Jennings died on 29 March 2024, four days after her 70th birthday.

Recognition In 2023, both Carol and Stuart Jennings were appointed honorary Vice-Presidents of the Alzheimer's Society, acknowledging their "extraordinary contribution to the field of dementia research". To further honour their legacy, the Alzheimer's Society and the Jennings family established the Carol Jennings Fellowship to support emerging researchers in Alzheimer's disease.

In May 2026, Jennings was awarded a posthumous honorary doctorate, DSc (Med), by University College London, in recognition of her contribution to research that helped establish the amyloid cascade hypothesis and ultimately paved the way for the first disease-modifying therapies for Alzheimer's disease. The degree was conferred by Professor Sir John Hardy at a UCL graduation ceremony, with Stuart Jennings accepting it on Carol's behalf. Hardy noted that her impact on the research was "immeasurable" and would continue to resonate for decades.

The Jennings vs Alzheimer's

In 2022, the BBC announced the commissioning of a feature documentary recounting the story of the Jennings family and their ongoing involvement in Alzheimer's research. The resulting film “The Jennings vs Alzheimer’s” was broadcast on BBC Two and BBC iPlayer on 13 May 2024 in the UK. Directed by Irish filmmaker Niamh Kennedy, the documentary received positive reviews from major newspapers, including The Guardian, The Times, and The Daily Telegraph. It won the award for the Best Science Documentary category at the 2024 Grierson Awards.

The Carol Jennings Fellowship

The Carol Jennings Fellowship was established by the Alzheimer's Society in 2023 to support early-career researchers in Alzheimer's disease. The fellowship honours Carol Jennings' legacy of advocacy and her family's contribution to advancing understanding of the genetic causes of Alzheimer's disease. 2024-2025: Dr. Chris Hardy (University College London) – Dr. Hardy's research focuses on the connection between hearing loss and dementia, developing new tests of "brain hearing" to help detect, diagnose, and track dementia. 2025-2026: Dr. Ian Harrison (University College London) – Dr. Harrison's research centres on boosting the glymphatic system to remove harmful proteins association with Alzheimer's disease.